1. Technical Field
The present invention relates to a technique for manufacturing an organic device using a conductive organic material.
2. Related Art
In recent years, organic devices using organic materials (conductive organic materials) having electric conductivity have been being developed. Organic devices are advantageous in that they are suitable for miniaturization and can be formed on a flexible substrate, and materials are inexpensive. Therefore, application to flexible displays has been investigated. For example, organic transistors and organic EL devices permit liquid processes such as an ink jet process using organic material solutions, thereby easily decreasing the process cost and facilitating the formation of large-area films. Therefore, this technical field is quite promising. In such an organic device, an ink jet process or a screen printing process is used for forming a film only in a specified region using an organic material solution, thereby realizing precise separate-coating (refer to, for example, Japanese Unexamined Patent Application Publication Nos. 2005-223286 and 10-12377).
The purposes of the above-described separate-coating include decreasing the amount of the solution used and the following. For example, a current leakage between adjacent fine wirings provided in a planar direction is decreased, and the electric characteristics are improved by optimization of a laminated structure. An example of improvement in the electric characteristics relates to an organic EL device. In an organic EL device, a luminescent layer, a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer are laminated to realize an organic EL device with a high luminous efficiency.
Organic devices requiring separate-coating of an organic material include large-area devices such as a display and a solar cell, which are advantageously formed by a liquid process. However, in recent years, the density and area of circuits constituting an organic device have been increasingly increased, and thus a solution pattern has been required to be made finer and thinner. As the density and area are increasingly increased, the separate-coating requires an advanced technique, thereby increasing the probability of occurrence of a defect. For example, when a solution is applied by an ink jet process, the solution may spread to an unnecessary portion or may be scattered or mistakenly dropped, thereby increasing the parasitic capacitance or causing a leak path.